The present invention relates generally to the manufacture of semiconductor integrated circuits and, more particularly, to a method and structure for forming self-aligned contacts.
As the technology for integrated circuits continues to shrink, the challenges of manufacturing smaller and more densely spaced devices increase. For example, connecting the semiconductor devices together requires that electrical contact elements (CA) be formed by etching holes, or vias, through an insulating material to contact the source/drain terminals of the semiconductor transistor device, which are directly adjacent the device gate stack of the transistor, without damaging or shorting the device. This requires good alignment of the CA vias to the spaces between the transistors where the source/drain contacts will be made.
Accordingly, there is a need for improved methods for forming CA contacts that are aligned to the transistor gates.